1. Field of the Invention
The present invention relates to the production of fine powders, and in particular to an apparatus for producing fine powder from organic material such as silk, wool and ramie.
2. Background Information
Organic materials such as silk, wool and ramie have special properties such as being high quality natural proteins, having moderate moisture absorption and retention properties and a high affinity with human skin. Such organic materials have been used, in powder form, in food products, beverages and cosmetic products. Also, method are known by which organic powders can be absorb into cotton fibers to produce fabrics which offer good drape characteristics as well as moisture-absorbing properties inherent in the cotton.
Organic materials such as silk and wool are widely used as high quality textile. Every year the textile industry produces large quantities of waste silk or wool fibers which cannot be used for textile processing. These fibers can be regenerated into organic powders. However, the process for doing this is messy problematic.
Compared with inorganic fiber, silk fibers, for example, not only have high strength but also high break intensity and high elongation, so they are very difficult grind into powder. Even when cut into short pieces the fibres still tends to wind together to form balls during grinding.
Presently, the best method of producing fine powder from silk is by chemical pretreatment to destroy its chemical bond and reduce its crystallinity. High energy irradiation can also be used to destroy the crystal structure. After pretreatment, the fibers are dissolved into an aqueous calcium chloride solution at high temperature, followed by a dialysis treatment to remove the salt; they are then dehydrated, dried and pulverized to yield a fine powder.